Question T3B03
From subelement T3 - T3B
What are the two components of a radio wave?
Why is this correct?
Radio waves are electromagnetic waves consisting of two fundamental components: electric and magnetic fields that are perpendicular to each other as they travel through space. Choice A (impedance and reactance) describes circuit characteristics, not wave components. Choice B (voltage and current) are electrical properties in conductors, not the fields that make up radio waves themselves. Choice D (ionizing and non-ionizing radiation) categorizes radiation types by energy level, not wave structure.
Memory tip
Remember 'EM' in electromagnetic — Electric and Magnetic fields are the two building blocks. When you see questions about wave composition or structure, think of these perpendicular fields traveling together at light speed, not circuit properties or energy classifications.
Learn more
Understanding electromagnetic wave structure is crucial for antenna design and propagation prediction. The perpendicular relationship between electric and magnetic fields determines wave polarization — vertical antennas primarily generate waves with vertical electric fields, while horizontal antennas create horizontal electric field orientations. This field orientation affects how signals couple between transmitting and receiving antennas, influencing signal strength and communication effectiveness across amateur frequency privileges.
Think about it
Why do you think the electric and magnetic fields must be at right angles to each other rather than parallel or at some other angle?